ORA-38104: ON 子句中引用的列无法更新

我有一个带有删除标志的简单表（记录应在此列中更新而不是删除）：

create table PSEUDODELETETABLE
(
  ID        NUMBER(8) not null, -- PKEY
  NAME      VARCHAR2(50) not null,
  ISDELETED NUMBER(1) default 0 not null
)

插入新记录时，我必须检查是否已存在与主键匹配但 ISDELETED = 1 的记录。在这种情况下，我必须将 ISDELETED 更改为 0 并更新其他列。因此我使用以下合并语句：

merge into ET.PSEUDODELETETABLE TARGET
using (select 1 as ID, 'Horst' as NAME from sys.dual) SOURCE
on (TARGET.ISDELETED = 1 and SOURCE.ID = TARGET.ID)
when matched then
  update set ISDELETED = 0, NAME = SOURCE.NAME
when not matched then
  insert values (SOURCE.ID, SOURCE.NAME, 0);

在 Sql-Server 上它运行得很好，但 Oracle 说：

ORA-38104: Columns referenced in the ON Clause cannot be updated: TARGET.ISDELETED

如果存在 IDELETED = 0 的匹配记录，我希望将主键违规作为例外，这就是为什么我无法将“TARGET.ISDELETED = 1”从 on 子句移动到 update 语句。

与已接受的响应相反，实际上有一种方法可以解决此问题：将有问题的位从 ON 子句中移出并移入更新语句的 WHERE 子句中：

merge into ET.PSEUDODELETETABLE TARGET
using (select 1 as ID, 'Horst' as NAME from sys.dual) SOURCE
on (SOURCE.ID = TARGET.ID)
when matched then
  update 
      set ISDELETED = 0, 
      NAME = SOURCE.NAME
  where TARGET.ISDELETED = 1 -- Magic!
when not matched then
  insert 
      values (SOURCE.ID, SOURCE.NAME, 0);